Charging and discharging control circuit and charging type power supply device

• US 6,329,795 B1
• Filed: 05/13/1999
• Issued: 12/11/2001
• Est. Priority Date: 05/15/1998
• Status: Active Grant

• Current Assignee: Ablic Inc. (MinebeaMitsumi Inc.)
• Original Assignee: Seiko Instruments Incorporated (Seiko Group)
• Inventors: Nakashimo, Takao
• Primary Examiner(s): Tso, Edward H.
• Application Number:
  US09/310,908
• Time in Patent Office: 943 Days
• Field of Search: 320/116, 320/118, 320/134, 320/136
• US Class Current: 320/134
• CPC Class Codes: H01M 10/441 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/46 Accumulators structurally combined with charging apparatus circuits for charging H02J7/00
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/00306 Overdischarge protection
• CPC Class Codes: H02J 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A charging and discharging control circuit has a construction which limits current consumption. A plurality of detecting circuits detect at least one of an over-charge voltage and an over-discharge voltage of an electric power source and output a corresponding signal. A control circuit receives an output signal of the detecting circuits and outputs a signal for controlling the charging and discharging of the secondary batteries. In order to limit current consumption, a single source current is provided to each of the detecting circuits. In a preferred embodiment, the electric power source comprises a plurality of serially-connected batteries and the detecting circuits each comprise a comparator for comparing a reference voltage with a voltage representing an output voltage of a respective battery. At least one of the positive power supply terminals and negative power supply terminals of the comparators are serially connected so that the power supply current of the charging and discharging control circuit is limited.

Claims

1. A charging and discharging control circuit comprising:

a plurality of detecting circuits for detecting at least one of an over-charge state and an over-discharge state of a plurality of serially-connected secondary batteries and outputting a corresponding signal; and

a control circuit for receiving an output signal of the detecting circuits and outputting a signal for controlling the charging and discharging of the secondary batteries, wherein positive power supply terminals and negative power supply terminals of the detecting circuits are serially connected so that the power supply current of the charging and discharging control circuit is conserved.

3. A charging and discharging control circuit according to claim 1;

wherein the detecting circuits each comprises a comparator for comparing a reference voltage with a voltage representing an output voltage of a respective secondary battery.

4. A charging and discharging control circuit according to claim 3;

further comprising a voltage dividing circuit for dividing output voltages of the respective secondary batteries and producing a plurality of divided output voltages, wherein respective divided output voltages are supplied to a comparator of each detecting circuit as the voltage representing an output voltage of the secondary battery.

5. A charging and discharging control circuit according to claim 4;

wherein the voltage dividing circuit comprises a plurality of serially-connected resistors for dividing the output voltage of the secondary batteries, and wherein the reference voltage and the resistance value of the resistors are selected so that an output of the respective comparators switch when a corresponding secondary battery enters an over-charge state.

6. A charging and discharging control circuit according to claim 5;

wherein the voltage dividing circuit comprises a plurality of resistors for dividing the output voltage of the secondary batteries, and wherein the reference voltage and the resistance value of the resistors are selected so that an output of the respective comparators switch when a corresponding secondary battery enters an over-discharge state.

7. A charging and discharging control circuit according to claim 3;

wherein the reference voltage is an over-charge voltage of the secondary batteries.

8. A charging and discharging control circuit according to claim 3;

wherein the reference voltage is an over-discharge voltage of the secondary batteries.

2. A charging type power supply device comprising:

a plurality of serially-connected secondary batteries;

a switch circuit for connecting the batteries to an external power supply terminals; and

a charging and discharging control circuit comprising a plurality of detecting circuits for detecting at least one of an over-charge state and an over-discharge state of the secondary batteries, and a control circuit for receiving an output of the detecting circuits and controlling the switch circuit to disconnect the secondary batteries from the external power supply terminal when one of an over-charge state and an over-discharge state is detected;

wherein at least one of positive power supply terminals and negative power supply terminals of the detecting circuits are serially connected so that the power supply current of the charging and discharging control circuit is conserved.

9. A charging and discharging control circuit according to claim 2;

wherein the detecting circuits each comprises a comparator for comparing a reference voltage with a voltage representing an output voltage of a respective secondary battery.

10. A charging and discharging control circuit according to claim 9;

further comprising a voltage dividing circuit for dividing output voltages of the respective secondary batteries and producing a plurality of divided output voltages, wherein respective divided output voltages are supplied to a comparator of each detecting circuit as the voltage representing an output voltage of the secondary battery.

11. A charging and discharging control circuit according to claim 10;

wherein the voltage dividing circuit comprises a plurality of serially-connected resistors for dividing the output voltage of the secondary batteries, and wherein the reference voltage and the resistance value of the resistors are selected so that an output of the respective comparators switch when a corresponding secondary battery enters an over-charge state.

12. A charging and discharging control circuit according to claim 11;

wherein the voltage dividing circuit comprises a plurality of resistors for dividing the output voltage of the secondary batteries, and wherein the reference voltage and the resistance value of the resistors are selected so that an output of the respective comparators switch when a corresponding secondary battery enters an over-discharge state.

13. A charging and discharging control circuit according to claim 9;

wherein the reference voltage is an over-charge voltage of the secondary batteries.

14. A charging and discharging control circuit according to claim 9;

wherein the reference voltage is an over-discharge voltage of the secondary batteries.

15. A charging and discharging control circuit comprising:

a plurality of detecting circuits for detecting at least one of an over-charge state and an over-discharge state of a plurality of serially-connected secondary batteries and outputting a corresponding signal; and

a control circuit for receiving an output signal of the detecting circuits and outputting a signal for controlling the charging and discharging of the secondary batteries;

wherein the detecting circuits each comprise a comparator for comparing a reference voltage with a voltage representing an output voltage of a respective secondary battery, and a voltage dividing circuit comprised of a plurality of serially-connected resistors for dividing output voltages of the respective secondary batteries and producing a plurality of divided output voltages, respective divided output voltages being supplied to a comparator of each detecting circuit as the voltage representing an output voltage of the secondary battery; and

wherein the reference voltage and the resistance value of the resistors are selected so that outputs of the respective comparators switch when a corresponding secondary battery enters one of an over-charge state and an over-discharge state; and

wherein positive power supply terminals and negative power supply terminals of the detecting circuits are serially connected so that the power supply current of the charging and discharging control circuit is conserved.

16. A charging and discharging control circuit according to claim 15;

wherein the reference voltage is one of an over-charge voltage and an over-discharge voltage of the secondary batteries.

17. A charging type power supply device comprising:

a plurality of serially-connected secondary batteries;

a switch circuit for connecting the batteries to an external power supply terminal; and

a charging and discharging control circuit comprising a plurality of detecting circuits for detecting at least one of an over-charge state and an over-discharge state of the secondary batteries, and a control circuit for receiving an output of the detecting circuits and controlling the switch circuit to disconnect the secondary batteries from the external power supply terminal when one of an over-charge state and an over-discharge state is detected;

wherein at least one of positive power supply terminals and negative power supply terminals of the detecting circuits are serially connected so that the power supply current of the charging and discharging control circuit is conserved;

wherein the detecting circuits each comprises a comparator for comparing a reference voltage with a voltage representing an output voltage of a respective secondary battery, and a voltage dividing circuit for dividing output voltages of the respective secondary batteries and producing a plurality of divided output voltages;

wherein respective divided output voltages are supplied to a comparator of each detecting circuit as the voltage representing an output voltage of the secondary battery;

wherein each voltage dividing circuit comprises a plurality of serially-connected resistors for dividing the output voltage of the secondary batteries; and

wherein the reference voltage and the resistance value of the resistors are selected so that an output of the respective comparators switch when a corresponding secondary battery enters one of an over-charge state and an over-discharge state.

18. A charging and discharging control circuit according to claim 17;

wherein the reference voltage is one of an over-charge voltage and an over-discharge voltage of the secondary batteries.

19. A charging and discharging control circuit comprising:

a plurality of detecting circuits for detecting at least one of an over-charge state and an over-discharge state of an electric power source; and

a control circuit for receiving output signals from the detecting circuits and for disconnecting the electric power source from an external device when one of an over-charge state and an over-discharge state is detected for controlling charging and discharging of the electric power source;

wherein a single supply current is provided to the plural detecting circuits to conserve supply current;

wherein the electric power source comprises a plurality of serially-connected secondary batteries;

wherein the detecting circuits each comprises a comparator for comparing a reference voltage with a voltage representing an output voltage of a respective secondary battery, and a voltage dividing circuit comprising a plurality of serially-connected resistors for dividing output voltages of the respective secondary batteries and producing a plurality of divided output voltages;

wherein respective divided output voltages are supplied to a comparator of each detecting circuit as the voltage representing an output voltage of the secondary battery; and

wherein the reference voltage and the resistance value of the resistors are selected so that an output of the respective comparators switch when a corresponding secondary battery enters one of an over-charge state and an over-discharge state.

20. A charging and discharging control circuit according to claim 19;

wherein the reference voltage is one of an over-charge voltage and an over-discharge voltage of the secondary batteries.

21. A charging and discharging control circuit comprising:

a plurality of detecting circuits for detecting at least one of an over-charge state and an over-discharge state of a secondary battery and outputting a corresponding signal; and

a control circuit for receiving an output signal of the detecting circuits and outputting a signal for controlling the charging and discharging of the secondary battery;

wherein positive power supply terminals and negative power supply terminals of two or more of the detecting circuits are serially connected so that the power supply current of the charging and discharging control circuit is conserved.

22. A charging and discharging control circuit according to claim 21;

wherein the secondary battery comprises a plurality of secondary batteries.

23. A charging and discharging control circuit according to claim 22;

wherein the detecting circuits each comprises a comparator for comparing a reference voltage with a voltage representing an output voltage of a respective secondary battery.

24. A charging and discharging control circuit according to claim 23;

wherein each detecting circuit further comprises a voltage dividing circuit for dividing output voltages of the respective secondary batteries and producing a plurality of divided output voltages, the respective divided output voltages being supplied to a comparator of each detecting circuit as the voltage representing an output voltage of the secondary battery.

25. A charging and discharging control circuit according to claim 24;

wherein the voltage dividing circuit comprises a plurality of serially-connected resistors for dividing the output voltage of the secondary batteries, and wherein the reference voltage and the resistance value of the resistors are selected so that an output of the respective comparators switch when a corresponding secondary battery enters an over-charge state.

26. A charging and discharging control circuit according to claim 25;

wherein the voltage dividing circuit comprises a plurality of resistors for dividing the output voltage of the secondary batteries, and wherein the reference voltage and the resistance value of the resistors are selected so that an output of the respective comparators switch when a corresponding secondary battery enters an over-discharge state.

27. A charging and discharging control circuit according to claim 23;

wherein the reference voltage is an over-charge voltage of the secondary batteries.

28. A charging and discharging control circuit according to claim 23;

wherein the reference voltage is an over-discharge voltage of the secondary batteries.